JPS58112618A - Manufacture of heat collecting pipe for solar heat - Google Patents

Abstract

PURPOSE:To simply and inexpensively manufacture a solar heat collecting pipe having excellent heat transferring characteristics and high strength, by housing a heat storing pipe in a recessed groove of an unit fin constitutig a heat collecting fin, and press-welding mutually opposing pieces, provided along the groove, from outsides. CONSTITUTION:A heat collecting fin A, made of a raw material such as aluminum, consists of divided unit fins and has a recessed groove 2 and heat collecting flanges. Unit fins 1... are arranged through very small gaps 5 formed for preventing the deformation caused by thermal expansion; a heat storing pipe B made of a raw material such as copper is housed in recessed grooves 2.... Next, tip parts 9 and 9 of a pair of opposing pieces 4 and 4, mutually opposing in a strip-shape at the opening ends of the groove 2, are pressed from outsides to make both tip parts meet, and further, the meeting parts are cold press-welded to form a jointing part C. Thus, the inner wall 6 of the previously cleaned groove 2 and the inner surfaces 7 and 7 of the root parts of the pieces 4 and 4 are made into close contact with the outer peripheral surface 8 of the pipe B, thereby a solar heat collecting pipe having excellent heat transferring characteristics and mechanical strength is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a solar heat collecting pipe comprising a heat absorbing pipe serving as a heat medium path and heat collecting fins attached to the outside of the heat absorbing pipe for heat conduction.

Conventionally, this type of solar heat collecting tube has been installed by placing a heat absorbing pipe on a heat collecting fin on a flat plate and making explosive contact between the two. According to this, not only is the mounting strength weak,
There was a drawback that the heat transfer efficiency to the heat absorption pipe was poor because there were few contact points between the heat collecting fin and the heat absorption pipe.

Recently, in order to eliminate the above-mentioned drawbacks, grooves have been provided in the heat collecting fins, and heat absorption pipes have been installed in the grooves. Furthermore, in consideration of heat transfer efficiency and cost, a system in which the material of the heat collecting fins is Aj and the material of the heat absorbing pipe is Cu has been put into practical use. According to this, it was pointed out that the heat loss rate is large because a large amount of heat is released from the exposed portion of the heat absorption pipe, which has good heat transfer efficiency. In addition, the heat-absorbing pipe that receives heat transfer has a difference in thermal expansion coefficient between the exposed part and the covered part within the groove, so the heat-absorbing pipe is likely to separate within one groove, and the heat transfer efficiency from the heat collecting fins is reduced. tended to decline year by year.

Very recently, as a solution to the above drawbacks, the heat collecting fins are provided with pipes instead of grooves, and the heat absorption pipe is completely covered with the pipe of the heat collecting fins by inserting a collecting vibrator into the pipe, which is a double pipe. A manufacturing method is provided. Although the double pipes must be tightly attached, it is technically difficult to tightly insert the heating pipe into the pipe of the heat collecting fin. To do this, it is necessary to loosely insert a heat-generating pipe with a smaller diameter than the heat-collecting fin pipe into the pipe, and then expand the converging vibrator so that the outer circumferential surface of the heat-generating pipe and the inner surface of the heat-collecting fin come into close contact. was there. However, expanding the heat-forming pipe is extremely troublesome, has low work efficiency, and is expensive.

SUMMARY OF THE INVENTION Therefore, the present invention aims to solve the above-mentioned conventional disadvantages, and includes constructing a heat collecting fin by one row of divided unit fins, and a concave groove in each unit fin. A step of providing a pair of opposing pieces facing each other in a band shape over the entire length of the opening end of the fin, storing a heating pipe in the groove of each unit fin, and simultaneously pressing the opposing pieces over their entire length from both outsides. This method is characterized by comprising a step of bringing together the tips of the facing pieces, and a step of sequentially cold-pressing the joined parts of the facing pieces.

Hereinafter, an explanation will be given based on an embodiment illustrating the present invention.The endothermic blade B is molded using gold a selected from the group consisting of copper and stainless steel. The heat collecting fin A is constructed by arranging unit fins each having a desired overall length in the length direction. The unit fin 1 has a desired total length obtained by dividing the length of the straight part of the heating pipe B into several parts, and is provided with a groove 2 having a size that allows the heating pipe B to be accommodated without being press-fitted. A flat plate-shaped heat collecting collar 3 is integrally formed on both outer sides of the holder.

From the opening end of the recess 111j2, a pair of opposing pieces 4.4
are formed in opposing protrusions in a band shape over the desired entire length.

The opposing piece 4.4 has a length sufficient to form a double tube between the heating pipe B and the groove 2.

First, with the opposing pieces 4, 4 facing upward, the unit fins are arranged at minute intervals 5 in their respective length directions. The minute spacing is set to the minimum value in consideration of the lengthwise extension of each unit fin 1.

The heating pipe B is housed in each groove 2 of each unit fin without being press-fitted. In this storage process,
The inner surface 6 of the groove 2 and the inner surface 7.7 of the proximal end portions of the opposing pieces 4, 4 are not in close contact with the outer circumferential surface 8 of the accommodation vibe B. These contact surfaces 6, 7.・7 and 8 have been cleaned.

Next, after the storage process, one unit fin 10 facing piece 4,
4 from both outsides at once over the entire length. By this suppression, the inner surface 6 of the groove 2 of one unit fin 1 and the inner surface 7.7 of the proximal end of the opposing piece 4.4 are brought into close contact with the outer circumferential surface 8 of the heating pipe B, while the opposing piece 4. 4 tip 9.9
A process of meeting is performed. This meeting step is sequentially performed on each opposing piece 4 of the other unit finch.

After the meeting step, the base 1 of the joined portion of the facing pieces 4, 4
0.10 is divided into parts and cold pressure welded in sequence.

That is, since large-scale equipment is required to cold-press the entire length of the opposing pieces 4.4 at once, the entire length of the opposing pieces 4.4 is further divided into arbitrary lengths and the cold welding is performed sequentially starting from the ends. Perform pressure welding. According to experiments, the appropriate contact force is 80-120Kt.
/- is obtained. The tip portion of the opposing piece 4.4 located above the cold welded joint C is cut at the imaginary line position, if necessary.

The above process is implemented by press bonding as shown in FIG. That is, the pair of suppressing parts 11.11 constituting the suppressing press are approximately the same length or slightly longer than the full length of the unit fin 1, and the opposing pieces 4.11 are moved forward by each other.
4 at once from their tips 9°9. Furthermore, the pair of press-contact parts 12.12 constituting the press-contact press are elongated parts obtained by dividing the entire length of the unit fin 1 into several parts, and the base lB10.1 (1 Cold pressure welding is carried out partially depending on the length, and then the whole length is sequentially joined from one side to the other. Pressing press and pressure welding press are
This is carried out in a continuous process at intervals during the same feeding process.

Of course, they may be arranged individually.

According to the above manufacturing method, each pair of opposing pieces 4 are opposed in a band shape over a desired entire length from the open end of the concave groove 2 of each unit heat collecting fin constituting the heat collecting fin A.
The inner surface T of the proximal end of ... and the inner surface 6 of the concave groove 2 ...
... are in full contact with the outer circumferential surface 8 of the heat-absorbing pipe B, so heat transfer from each unit heat collecting fin to the heat-absorbing pipe B is carried out over the entire outer circumferential surface 8 of the heat-absorbing vibe B, increasing the heat transfer efficiency. can be improved.

In addition, since the heat absorption pipe B is completely covered with the concave groove 2 and the base end inner surface 7 of the opposing piece 4, making it a double pipe, the mechanical strength against thermal expansion is improved. Can be increased. ζ
Furthermore, the entire length of the facing pieces 4, 4 is pressed at once to meet them,
After that, cold pressure welding is sequentially applied to the parts, so that the endothermic pipe B is not deformed during processing, and a tightly fitted double pipe can be manufactured.

FIG. 5 shows another embodiment, in which 20 is a unit fin 1.
The concave groove 21 extends from the end and is a facing piece extending from the end, and the heat collecting claws are not extended.

According to this embodiment, it is possible to manufacture a double pipe without intervening a minute gap in the length direction of the heat absorption pipe B, and in addition, the heat collecting collar 3 . . . can be provided with a minute gap PJ51. This makes it possible to prevent deformation of the heat collecting collar 3 due to expansion.

Furthermore, the minute spacing 5 can be uniformly set by the abutting arrangement of the extension portions 20 and 21.

In each of the manufacturing methods described above, a pair of pressure welding parts constituting the pressure welding press has been described, but continuous pressure welding can be performed by placing a plurality of pressure welding parts.

In addition, although the explanation has been given on the case where the accommodation flange 3 of the unit fin 1 of the heat collecting fin A is in the form of a flat plate, if the structure is such that the facing piece 4.4 is provided at the open end of the groove 2, It is possible to manufacture the heating collar in a cylindrical shape or in any other shape.

As explained above, according to the present invention, a double solar collector tube can be manufactured by joining opposing pieces and cold welding without requiring the conventional tube expansion work, improving work efficiency. This enabled us to reduce work costs. In particular, since it is constructed from an array of unit fins, it is possible to press-form each unit fin, and the press-formed opposing pieces can be further divided and cold-welded one after another, making it possible to manufacture the unit fins without the need for large equipment. By using one row of , it was possible to prevent deformation due to thermal expansion in the length direction.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a heat absorbing bag and a heat collecting fin used in the manufacturing method according to the present invention, FIGS. 2(a) to (e) are schematic diagrams of the same process, and FIG. 3 is a perspective view of a solar heat collecting tube. Figure 4 (A)
, (B) is a schematic plan view of the process similar to FIG. 2, and FIG. 5 is a plan view of a solar heat collection tube showing another embodiment. A... Heat collecting fin, B... Heat absorption pipe, 1... Unit fin, 2, 20... Concave groove, 3... Heat collecting collar,
4.21... Opposing piece, 7... Base end inner surface, 9...
tip, 10--base of joined part; Patent applicant: Hakusan Seisakusho Co., Ltd.

Claims (1)

[Claims] A heat collecting fin is constituted by one row of divided unit fins, and a pair of opposing pieces are provided at the open ends of the grooves of each unit fin in a band-like manner over the entire length of each unit fin. a step of simultaneously pressing the entire length between the pair of opposing pieces from the outside so that all the tips of the opposing pieces meet; and a step of sequentially cold-pressing the joined parts of the opposing pieces. A method for manufacturing a solar heat collector tube, characterized by comprising: